Biofunctional photoelectrochemical immunosensor based on Ag– AgI/BiOI– Bi2O3 for the rapid detection of squamous cell carcinoma antigen

composite material, synthesized via a one-step hydrothermal method, which exhibited a strong photoelectric response under visible light irradiation. This composite material enhanced the electron-hole separation and conductivity, significantly improving the PEC performance and enabling highly sensitive and specific detection of SCCA. Experimental results indicated that the sensor displayed an excellent logarithmic linear relationship within the SCCA concentration range of 0.0001 ng/mL to 10 ng/mL, having a detection threshold as low as 0.04 pg/mL. Furthermore, the sensor exhibited high accuracy and stability accuracy and stability for the detection of real serum samples. Compared with previously reported methods, this PEC immunosensor offers the advantages of simpler operation, a lower detection limit, and higher sensitivity, providing a novel and effective strategy for the clinical detection of SCCA.